He wanted to target Muslims from Gambia serving in the army as part of a contingent of Commonwealth soldiers.

Khan, who was once a promising footballer, was radicalised during several trips to Pakistan. He began to run equipment to terrorists in Afghanistan, but came up with the kidnap plot when his sick mother and his superiors in Afghanistan prevented him from going abroad to fight.

He hoped the plot would cause panic across the country and dissuade British Muslims from joining the Armed Forces. However he was taped discussing the plot and was arrested in January 2007 when he was believed to be just days from carrying out the attack.

Khan, from Alum Rock, Birmingham, pleaded guilty to plotting the kidnap and execution of a soldier and was sentenced to life in prison with a minimum of 14 years in jail.

Sentencing him, Mr Justice Henriques said: "So rampant are your views, so excitable your temperament, so persuasive your tongue and so imbued with energy are you, it's quite impossible to predict when, if ever, it will be safe for you to be released into the public.

"It was a plot whose purpose was to undermine democratic government, to demoralise the British Army and to destabilise recruitment, and to cause anguish to the then Prime Minister of the day and the loyal citizens of the country."

Three other men were sentenced for involvement in Khan’s supply network and another admitted knowing about the plot, but failing to inform the police.